1. Field of the Invention
The invention relates to a signal detection method, and more particularly to a method of determining the sequence of detected signals.
2. Description of the Related Art
A liquid crystal display may have many signal sources, such as analog signals (D-SUB), digital signals, video signals and various other signals. A conventional liquid crystal display must detect terminals for different signal sources one-by-one to determine which terminal is conducting signals and for receiving the signals when the liquid crystal display is turned on. The signal detection is performed manually or automatically in the conventional liquid crystal display.
A conventional manual signal detection method is shown in FIG. 1. When the liquid crystal display is turned on, the liquid crystal display is manually switched to a desired terminal, for example to a D-SUB terminal as shown in step 101 of FIG. 1, to a DVI terminal as shown in step 102, or to an S-video terminal as shown in Step 103. Steps 104 and 105 of FIG. 1 show the manual switch to other two terminals. In spite of the fast and direct operation of the manual switch, human intervention is required.
A conventional automatic signal detection method is shown in FIG. 2. When the liquid crystal display is turned on, the terminals of the liquid crystal display are detected automatically one-by-one to determine the terminal conducting signals as shown in step 201 of FIG. 2. When signals at one terminal are detected, the liquid crystal display is switched automatically to the terminal, for example to the D-SUB terminal as shown in step 202. Note that when the detected signals are unstable, the liquid crystal display detects the terminal with signal traffic periodically as shown in step 203 until the signals are stable. When the signals are interrupted, the automatic detection is resumed. Although automatic detection is convenient, detecting terminals one-by-one is time consuming.